CNS Infections Flashcards
Meningitis
Inflammation of the leptomeniniges
Encephalitis
Infection of the brain parenchyma - neurons and glial cells
Brain Abscess
Localized brain infection
What is fungal meningitis associated with?
Immune-compromisded state
What is aseptic meningitis associated with?
Viral meningitis
Common cause of meningitis in neonates…
– Group B streptococci
– Aerobic Gram-negative bacilli (E. coli)
Common cause of meningitis in infants less than 1 year…
– S. pneumoniae (Pneumococcus)
– Haemophilus influenzae – less common now due to vaccination
Common cause of meningitis in teenagers…
– Neisseria meningitis
– H. influenzae
– S. pneumoniae
Common cause of meningitis in adults…
– S. pneumoniae
– Neisseria meningitidis
Common cause of meningitis in elderly…
– L. monocytogenes
– Pseudomonas aeruginosa (less common)
What are the causative agents of chronic meningitis?
- TB
- Fungal - Cryptococcus/Histoplasma
- Syphilis
- Borrelia (rare)
What cells are found with bacterial meningitis in the CSF?
Neutrophils
What cells are found with viral meningitis in the CSF?
Lymphocytes
What cells are found with TB meningitis in the CSF?
Lymphocytes
What is the most common cerebral parasite?
Taenia solium - cysticercosis
How can cysticercosis present?
Seizures
What are the TORCH infections?
Toxoplasmosis Others Rubella CMV HSV
What viruses prefer to attack motor neurons?
Polio Virus and Enterovirus
What matter of the CNS is more involved with viral encephalitis?
Greater gray matter involvement
Polio Encephalitis
Fecal-oral transmission with infection and destruction of anterior horn cells - LMN
What are Negri bodies indicative of?
Rabies
What area of the brain does Herpes encephalitis localize to?
Medial temporal lobes - edema, hemorrhage and necrosis
Who are the people affected with CNS infections by CMV?
Neonates and AIDs patients
What is the cause of progressive multifocal leukoencephalopathy?
Caused by JC virus - usually the immuno compromised
What are the characteristics of progressive multifocal leukoencephalopathy?
– Loss of myelin (with axonal sparing)
– Bizarre astrocytes
– Oligodendroglial inclusions
What is characteristic of HIV encephalitis?
Widespread microglial nodule encephalitis with multinucleated giant cells
Vacuolar Myelopathy
– Spastic paraparesis with hyperreflexia and ataxia
– Vacuolation of spinal cord white matter
